It is necessary in myriad commercial product applications to embed a sensing device into a rubber article for the purpose of sensing a physical parameter of the article. One such application is the incorporation of a relatively rigid RFID transponder into a tire in order to detect and measure the pressure within the tire and communicate the pressure level to an external reader. Efforts at achieving transponder carriers for rubber articles such as a tire that can withstand forces resulting from continuous tire deformation and flexure during manufacture and operation have proven difficult. Structural damage to the transponder and/or carrier package can result from the stress concentrations from manufacture and use of the tire and cause transponder malfunction.
Alternative approaches to securing a rigid transponder, such as an RFID tag, and its associate carrier into a tire have been attempted with less than satisfactory results. One such approach has been to embed the transponder into tire by means of a conventional tire repair patch. Such an approach is advantageous in that the post manufacture introduction of a transponder into a tire can then be seamless, utilizing existing tire repair production lines. However, utilizing conventional patch configurations for applying a rigid transponder into a tire has not proven durable or reliable. Under certain conditions, a rigid RFID tag within a conventional tire patch may be ejected due to the stress concentrations imposed by the extreme stiffness differences between the patch and the tag during patch flexing. Moreover, patches are generally assemblies of green compound layers that are cured in compression molds. The incorporation of a tag into a patch may, due to the addition of the tag geometry, trap small quantities of air and limit any expansion of the material because of trapped air around the tag. The structural integrity of the resulting patch/tag assembly may as a result be compromised, causing separation between the tag and patch during use.
Consequently, there is a need for a convenient, cost effective transponder carrier construction that can embed a transponder, such as an RFID tag, into a tire or other rubber article. Such a construction should be capable of achieving an effective incorporation of the transponder to cured rubber or in articles in the green state. The construction should be durable at the transponder circumference to rubber interface in order to minimize the potential for transponder separation from the tag.